Apparatus for the control of highway crossing signals



Aug. 10, 1937. g, STAPLES 2,089,919

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS original Filed- March 13. 1935 2 Sheets-Sheet 1 29 C I y @5526 H 79 x is? T I fl I i V c (Ia xiv d ,5 d I 51- j 66 ml 1%? /27 7 1? 1? J6 30 l [H r-o 50 y 37 J4 INVENTOR Z Cir awfold E. Szaplas BY mm HIS ATTORNEY Aug. 10, 1937. c, STAPLES 2,089,919

- APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Original Filed March 13, 1935 2 Sheets-Sheet 2 Time 60 in Secondg Flgd.

1020;04050607080 I i1 5 Ln Seconds ,NVENT Cpawfoldfi'. S ples BY $1M HIS ATTORNEY Patented Aug. 10, 1937 UNITED STATES PATENT OFFICE APPARATUS FOR THE CONTROL OF HIGH- WAY CROSSING SIGNALS Application March 13, 1935, Serial No. 10,869 Renewed December 4, 1936 27 Claims.

My invention relates to apparatus for the control of highway crossing signals, and has for an object the provision of apparatus effective to determine the speed of a train as it approaches a highway intersection and then start the operation of the highway signal before the train reaches the intersection a time interval which is in accordance to the speed of the train. Another ob ject of my invention is the provision of apparatus of the type here involved wherewith a single operating unit is effective to actuate both a speed measuring mechanism and a highway crossing signal. A further object of my invention is the provision of apparatus of the type here involved wherein a time measuring means includes a circuit controlling element which is moved away from and toward a control position in accordance with cam surfaces and a desired rate of movement in each direction is effected. Other objects and O advantages of my invention will appear as the specification progresses.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic View of one form of apparatus that may be employed. in carrying out the embodiment of my invention. Fig. 2 is a plan view partly diagrammatic of a portion of the apparatus of Fig. 1. Fig. 3 is a detail view of the biasing spring for the restoring cam of Fig. 1. Figs. 4 and 5 are diagrams illustrating certain characteristics of the apparatus of Figs. 1, 2 and 3.

Similar reference characters refer to similar parts in each of the views.

Referring to Fig. 1, the reference characters I and I designate the track rails of a stretch of railway track over which traffic normally moves in the direction indicated by an arrow and which 49 stretch is intersected by a highway H. Two highway crossing signals S! and S2 are located adjacent the intersection and are indicated on the drawings by symbols commonly used in the art to designate a flashing light highway crossing 5 signal. As is common practice, these two signals are set for one to be plainly exhibited to highway traffic approaching the crossing in one direction and the other signal to be plainly exhibited to highway traffic approaching the crossing from 50 the opposite direction. It will be understood, however, that my invention is not limited to any specific form of highway crossing signal and the form here shown is by way of illustration only.

As here shown, the track rails l and l are divided by the usualinsulated rail joints to form three track sections R,S, ST and TV, which sections are traversed successively in the order named by a train approaching the highway 1-1 when moving in the normal direction of traffic. Each track section is provided with a track circuit comprising a battery 3 connected across the track rails at one end of the section and a track relay designated by the reference character R plus an exponent corresponding to its location connected across the rails at the other end of the section. For the purpose of this description I shall refer to the track section RS as a measuring section, section S-T as an operating section, and the section TV as a positive operating section. As will appear hereinafter, the speed of a train as it traverses the measuring section R-S is measured, the highway signals SI and S2 are set into operation in accordance with this measured speed after the train has entered the operating section ST and positive operation of the signals SI and S2 occurs during the time the train occupies the section TV irrespective of whether it is moving or not.

In order to more easily understand the apparatus embodying my invention I shall assume a maximum speed for all trains approaching the highway H of miles per hour. I shall also assume a time interval of 20 seconds exhibit of the highway signals before a slow moving train reaches the intersection and that this interval is uniformly increased as the speed becomes greater until an exhibit of 30 seconds of the highway signals for a train traveling at the maximum speed of 60 miles per hour is provided. I shall further assume the measuring section RS to be 880 feet in length, that is, the section R,S is of such length that a train moving at the maximum speed of 60 miles per hour consumes approximately 10 seconds in advancing therethrough. The combined lengths of the operating section ST and the positive operating section TV are substantially 2640 feet since a train traveling at the maximum speed of 60 miles per hour moves 2640 feet in 30 seconds and, as above stated, a 30 seconds exhibit of the highway crossing signals before a train traveling at the maximum speed reaches the intersection is desired. The section TV is preferably just long enough, say 200 feet, that operation of the highway crossing signals with .a train occupying the intersection whether it is moving or not is assured. It follows that with the track arrangement here assumed the highway crossing signals S! and S2 are set into operation for a train traveling at the maximum speed immediately upon the train entering the operating section ST, but that for a train having a lower speed the starting of the operation of the signals SI and S2 is delayed after the train enters the operating section S-T, this delay being such that the period of operation of the highway signals before a train reaches the intersection becomes proportionally less as the speed becomes lower until at a speed of 20 miles per hour the period of operation is only 20 seconds whereas at the maximum speed the period of operation is 30 seconds. For speeds lower than 20 miles per hour the period of operation remains substantially constant at 20 seconds. It will be understood, of course, that my invention is not limited to the above-stated values of speeds, lengths of track sections and operating intervals of the highway crossing signals, and such values may be selected best suited for the location at which the apparatus is installed.

The operation of the signals SI and S2 is governed by an operating unit here shown as an oscillator or code transmitter designated as awhole by the reference character CT. This oscillator CT may take different forms but a preferred form is that described and claimed in Letters Patent No. 1,858,876, granted May 17, 1932, to Paul N. Bossart, for Coding apparatus. It is deemed sufficient for the present application to give but a brief description of this oscillator CT. A magnetic field structure 5 has mounted between itstwo poles PI and P2 a spindle 8 on which an armature 6 is fixed so as to swing freely between the pole pieces. The armature 6 and the spindle 8 are normally biased to the position illustrated in Fig. 1 by any convenient biasing means such as a coil spring not shown, and the armature 6 is adapted to be attracted toward the pole pieces of the field structure in response to a magnetic field created therein. As indicated schematically by dotted lines, three cam members 9, I and II are fixed on the spindle 8. These cam members 9, I0 and II are each effective when rotated with the spindle 8 in a manner to shortly appear, to actuate a pair of circuit controlling contact fingers. A field winding I is mounted on the field structure and is provided with a plurality .of energizing circuits all of which include the pair of contact fingers actuated by the cam member I I. When the relay R is deenergized and its back contact I2 is closed, a circuit is completed which extends from the B terminal of any convenient source of current such as a battery not shown, over wire I3, back contact I2 of relay R wire I I, winding I, contact I5I 6 actuated by the cam I I and thence to the opposite terminal 0 of the same source of current. In the event the track relay R is shunted and its back contact I1 is closed, or if the track relay R is shunted and its back contact. I8 is closed, a circuit extends from the B battery terminal over the back contact II of relay R or over the back contact I8 of the relay R wire I I, winding I, contact I5I6 and to the.

C battery terminal. It follows that as long as any one of the track relays R R and R is shunted, the field winding I is supplied with current, but that when all three of these relays are picked up the winding I is without current. With the winding I energized and a magnetic field created in the field structure 5, the armature 6 is attracted toward the pole pieces and the spindle 8 is rotated in a counterclockwise direction against the force of the bias. After a slight movement of the armature 6 in the counterclockwise direction, the cam member II actuates the contact finger I5 out of engagement with the contact finger I6 and the circuit clonnection therethrough is ruptured with the result that the field winding 7 is deenergized. The armature 6 rotates a' little farther and then its movement is reversed due to the bias and it swings clockwise toward its normal position. The cam member II is now rotated back toward its normal position and the contact I5I6 is again closed and the winding 1 is reenergized. Armature G swings clockwise slightly past its normal position due to the inertia of its parts and it is then again rotated in a counter-clockwise direction due to the influence of the magnetic field. Consequently, as long as any one of the track relays R R or R is shunted and the field winding I is supplied with current, the armature 6 oscillates at its natural period, the period of oscillation being determined by the bias and the weight of the parts. Although the period of oscillation may be any convenient frequency, I shall consider it to be 30 cycles per minute.

As stated above, the cam members 9 and II] are fixed on the spindle 8, and hence the cam members 5 and III are rotated in response to the operation of armature 6. The cam member 9 is so shaped that when rotated counter-clockwise the associated contact fingers I9 and 20 are forced apart to break engagement and open the circuit connection therethroughJout that when rotated in the clockwise direction within the limits of the movement of the armature 6, the contact fingers I9 and 26 remain in engagement to close the circuit connectiontherethrough, The cam member Ii] is so shaped that when rotated clockwise the associated contact fingers 2i 3 and 22 are forced apart to open the circuit connection therethrough but when rotated in the counter-clockwise direction within the limits of the movement of the armature 6, the contact fingers 2i and 22 remain in engagement. It follows that as the armature I5 is rotated counterclockwise the contact I9-2E3 is opened and as the armature 6 swings clockwise past its normal position the contact 2I-22 is opened, but that at all other times these two contacts are closed.

The contacts I92ll and 2I22 govern the circuits for lighting the lamps of the highway crossing signals SI and S2. With positive current supplied to the wire 23 in a manner to subsequently appear, current flows thence through contact I 92@ over wire 24, lamp 255 of signal SI and to the negative terminal C of the source of current. Branching from the wire 24 the current fiows over a circuit including wire I5, lamp 25 of signal S2 and to the negative termi nal C of the current source. Current also flows rom wire 23 through the contact 2!-22 and thence over wire 2? and the lamps 28 and 29 of signals SI and S2, respectively, in parallel and to the negative terminal C of the current source. It is to be seen, therefore, that with positive current supplied to the wire 23 and the oscillator CT inactive, both lamps of each signal SI and S2 are steadily illuminated, but that with the oscillator operated in the manner explained and the contacts I52il and 2I-22 alternately opened and closed, the lamps 25 and 28 of signal SI and the lamps 26 and 29 of the signal S2 are alternately flashed, the rate at which the signals are flashed being substantially 39 times per minute since the frequency of the oscillator CT is 30 cycles per minute.

The oscillator CT in addition to governing the operation of the highway crossing signals SI and S2 in the manner just described, also aotuates.

a time measuring mechanism effective to determine the speed of the train approaching the highway H and by which mechanism the time or" starting of the operation of the signals SI and S2 before the train reaches the intersection is gover ed. I shall now describe this time measuring mechanism which is designated as a whole by the reference character TE. A worm 36 is rigidly mounted on the spindle 8 and rocks a lever 35 pivoted at 32 and on which lever a pawl 33 is pinned for engaging with a ratchet gear 34 with the result that the ratchet gear 34 is rotated clockwise as viewed in Fig. 1, in response to oscillations of the armature 6 of the oscillator CT. A latch 35 holds the ratchet gear 34 on the return stroke of the pawl 33. The ratchet gear 34 is keyed to a shaft 36 journaled at 31 and (see 2). A gear 39 and a cam 40 are loosoiy mounted on the shaft 36 between the bearings 3'! and 38, and between the gear 39 and the cam 46 a clutch member 4| and two springs 42 and 43 are provided. The clutch member 4| is secured to the shaft 36 by a feather key not shown, and hence, it rotates with the shaft 36 and may be moved along the shaft toward either the gear 39 or toward the cam 46. The forked end of a lever 44 pinned at 45 rides in a slot 46 of the clutch member M. The lever 44 is baised upward as viewed in Fig. 2 by a spring 41 and is magnetic relationship with an electromagnet the arrangement being such that the magwhen energized is effective to draw the lever d4 downward as viewed in Fig. 2 against the force of the spring 41. It is to be seen, therefore, that magnet 48 when energized is'effective to move the clutch member 4| and spring 43 into frictional engagement with the cam 40 whereby the cam 46 is made to rotate clockwise in response to clockwise movement of the ratchet gear but that magnet 48 when deenergized permits the spring 4'1 to draw the lever 44 upward and move the clutch member 4! out of engagement with the cam 46 and into engagement with the 36 through the spring 32 and that gear is rotated clockwise in response to clockwise movement of the ratchet gear 34. In other words, the cam 46 is rotated clockwise in response to operation of the oscillator CT and ratchet gear when the magnet 48 is energized but is left tr e to turn on the shaft 36 when the magnet 33 is deenergized, whereas the gear 39 d clockwise in response to operation of ator CT and ratchet gear 34 when the magnet 48 is deenergized and is left free to turn on the shaft 36 when the magnet 48 is ener- The cam 40 is provided with a counterwe. t :1 and is so proportioned that it is immediately restored to its normal position, that is, to the position iliustrated in Fig. 1, whenever the magnet 48 is deenergized.

The gear 36 meshes with a gear 49 keyed to a shaft 56 which is journaled at 51 and 52 and on which shaft is keyed a restoring cam 53. A stationary spring case 54 has contained therein a coil spring 55 (see Fi 3) which is secured to the shaft 56 as well as to the case 54. The spring 55 is effective to bias the shaft 56 in the clockwise direction. Consequently, when the gear 36 is coupled to the shaft 36 through the clutch member 4! and is rotated clockwise, the gear 49, shaft 56 and cam 53 are rotated counterclockwise against the force of the spring 55 except when the mutilated portion 10 of gear 49 is adjacent the gear 39. Furthermore, when the gear 39 is released from the shaft 36 the spring 55 is elfective to rotate the shaft 56 and cam 53 clockwise unless the cam is restrained by other means in a manner to later appear.

The cams 40 and 53 are utilized to operate a time measuring member here shown as a contact controlling arm 56. The arm 56 is pivoted at 5'! and is provided with cam followers 58 and 56 positioned to ride on the cams 46 and respectively. A contact finger 6D is secured to the arm 56 by proper insulation and this contact finger 6? makes engagement with a stationary contact 6! when the arm 56 occupies the normal position, that is, the position illustrated by solid lines in Fig. 1, but breaks engagement with the contact 6| as soon as the arm 56 is rotated upward about its pivot 51. An armature 62 of suitable magnetic material and a second contact finger 63 are also secured to the arm 56, the contact finger 63 being properly insulated from the An electromagnet 64 is located for magnetic relationship with the armature when the arm 56 is rotated upward to a reverse position illus trated by the dotted lines in Fig. 1, and on the casing of the magnet 64 a s ionary contact 65 is secured for making engagement with the contact finger 63 when the arm is -moved to its reverse position. The function of te magnet 64 and the contacts 653-61 and 62G5 will appear when the operation of the apparatus is described.

In describing the operation of the apparatus, I shall assume the track sections PPS, S-T and T-V are unoccupied and the respective track relays are picked up so that the oscillator CT is inactive and the lamps of the highway ore signals S! and S2 are all dark. Further I shall assume the cams and 53 and the 56 occupy their normal positions as iliustrated the drawings. It is to be noted that in this mal position of the apparatus, the rot supplied with current from the B terminal. of: the current source over front contact 68 reiay R front contact 6! of relay R wire win ing of the magnet 48 and to the opposite minal C of the current source, and the gnet 48 is energized to attract the rover draw the clutch member 4! into engagement with the cam 40. A train approaching the highway H from the right and entering the measuring section R shunts the track relay R its back contact !2 is closed with the resuit that c to actuate the conta lamps of the highway crossing signs remain dark since the wire is connoo back contact 69 of the magnet 2-3 that tated, and hence the cam 49 since the magnet 68 is one to be approaching the highway H travelthe maximum speed of 60 miles per hour, it con-- sumes approximately in seconds in advancing through the measuring section 1 S and entering the operating section 6 re shunts the track relay R The cam 1 its movement caused by the fi..s i operation of the oscillator CT effects no upward movement of the arm 55 and, consequently, the contact 69-6! is still closed when the train enters the section ST. That is to say, this portion of the surface of the cam 49 is an arc of a circle, the center of which is the center of a shaft 36. The shunting of the track relay R and the closing of its back contact H continues the supply of current to the field winding 1 of the oscillator CT, with the result that the oscillator con-' tinues to operate as long as the train occupies the section S-T notwithstanding the fact the rear of the train may vacate the section R-S and the track relay B may be picked up. Since the magnet 48 is deenergized and its back contact 69 is closed when the track relay R is shunted, current is supplied to the signals SI and S2 for illumination of their respective lamps. This circuit is traced from the B battery terminal over contact 666! operated by the arm 56, back contact B9 of magnet 58, wire 23, contacts l9-26 and 2l-22 in parallel and thence to the lamps of the signals SI and S2 as previously traced. Since the cams 9 and it are now alternately opening and closing the contacts l929 and 2l22, the tWo lamps of each of the signals SI and S2 are alternately flashed to exhibit a flashing signal to the highway users. When this train advances and enters the section TV and the track relay R is shunted, the field winding 1 of the oscillator CT is still supplied with current over the back contact N3 of the relay R and hence the si nals S! and S2 are flashed until such time as the rear of the train has advanced to the left of the highway H and vacated the section TV, since the magnet 48 is deenergized with relay R released. Inasmuch as the combined lengths of the sections S-T and TV are equal to 2640,

feet, there is a 30 seconds operation of the highway signals before the train traveling at the max- 40 imum speed of 60 miles per hour reaches the intersection. During the entire time the train occupies the sections ST and TV the ratchet gear 94 is rotated clockwise and the gear 39 is driven clockwisesince the magnet 48 is now deenergized and the clutch member 4| is forced into frictional engagement with the gear 39 due to the spring 47. Rotation of the gear 39 causes no rotation of the gear 59 at this time, however, since the teeth of the portion 79 of the gear 59 are cut away. The spring 55 secured to the shaft 59 is so proportioned and adjusted that it is effective to hold the shaft 56, gear 49 and cam 55 in the normal position where the cam 53 is in engagement with the cam follower 59 of the arm 56, but it is not of sufficient force to rotate the cam 53 against the Weight of the arm 56 at such time as the gear 39 is released and free to turn on the shaft 36. Consequently, for a train traveling at the maximum speed of 60 miles per hour the cam 39 is rotated clockwise during the time the train is advancing through the measuring section but with no movement of the arm 56, the highway crossing signals are flashed for 30 seconds prior to the arrival of the'train at the intersection and they continue to flash until the rear end of the train has passed beyond the highway and cleared the section TV. The cam 46 is restored to its normal position immediately upon the train entering the section S-T due to the influence of the counterweight H, since the magnet 38 is now deenergized.

In the event a train approaches the highway H traveling at a speed less than the maximum speed, an operating interval difierent from the 30 seconds interval of operation obtained for the angular distance about its pivot.

maximum speed is effected, the interval decreasing from 30 seconds in proportion to the decrease in the speed. I shall now assume a train traveling at 40 miles per hour approaches the highway. The relay R is shunted and the oscillator CT is set into operation as this train enters the measuring section R-S the same as explained for the train traveling 60 miles per hour. The train traveling 40 miles per hour consumes approximately 15 seconds in advancing through the sec tion RS and entering the section S-T. During this 15 seconds the cam 49 is rotated clockwise since the magnet 48 is energized, and during the first 10 seconds the cam 36 is rotated there is no upward movement of the arm 56 due to the circular surface of the cam as explained before, but the surface of the cam 49 is so shaped that after the first 10 seconds movement thereof the arm 56 is raised at a variable rate. In other words, the cam 49 is so shaped that from each one second operation of the cam after the first 10 seconds period the arm 56 is caused to move a different angular movement about its pivot 57, this angular movement progressively increasing for a limited time. The result of this upward movement of the arm 56 is to cause the contact 69 to move away from engagement with the stationary contact 6!. During the upward movement of the arm 56 the spring 55 is effective to rotate the shaft 50 and cam 53 clockwise with the result that the cam 53 follows along after the arm 55 maintains its engagement with the cam follower 59. The gear 49 on the shaft 50 is now brought into mesh with the gear 69 but since the gear 39 is now free to turn on the shaft 36 it offers but slight opposition to the spring 5 When this train advances and enters the section S-T and shunts the track relay R the magnet 48 is deenergized as previously explained. The immediate eifect of deenergizing the magnet 56 is to release the clutch member 4! from the cam 46 and to permit the clutch member ll to move into frictional engagement with the gear 39 under the influence of spring 41. The cam 49 upon being released is at once restored to its normal position due to the counterweight ll. Engagement of the gear 39 by the clutch member 6! is eifective to cause the cam 53 to be rotated counter-clockwise from the position to which it had advanced along with the arm 56 back toward its normal position in opposition tothe spring 55, the arm 56 following the cam 53 due to the weight of its parts. The surface of the cam 53 is so shaped as to cause a uniform rate of movement of the arm 56, that is, for each one second operation of the cam 53 the arm 56 is moved an equal As here shown, the parts areso proportioned that for the train traveling at the speed of 40 miles per hour the arm 56 is moved back to its normal position from the position to which it had been advanced by the cam 49 during the l5-seconds the train was advancing through the measuring section in approximately 20 seconds. Since the train traveling 40 miles per hour requires approximately 45 seconds to travel the 2640 feet between the entrance of the section S-T and Again, a train traveling 20 miles per hour consumes 30 seconds in moving through the measuring section RS and entering the operating section S-T. The cam 48 is rotated clockwise during this 30 seconds period and is then released and allowed to swing back to its normal position. When this train occupies the operating section ST the cam 53 is rotated counter-clockwise in response to operation of the oscillator CT as explained for the previous train. The cams 46 and 53 are so shaped that the arm 56 is moved upward by the cam 46 during the 30 seconds the train occupies the measuring section to a position where it requires substantially 70 seconds operation of the cam 53 before the arm 56 is restored to its normal position and the contact 606| is closed. Since a train of a speed of 20 miles per hour requires 90 seconds to advance the 2640 feet from the entrance of the section ST to the highway H, it follows that 20 seconds operation of the signals SI and S2 is effected before the train reaches the intersection.

The curve tacu of Fig. 4 illustrates the time the highway crossing signals are to be operated for the different speeds up to the maximum speed of 60 miles per hour, as arbitrarily assumed in the foregoing description. The curve 157's illustrates the time consumed in the measuring section RS by trains of different speeds and which time determines the upward movement of the arm 56. The curve tsv illustrates the time required by trains of different speeds to advance from the entrance of the operating section S-I to the intersection. The curve tsm is approximately the difference between the curve tso and the arbitrary curve tzru and illustrates the delay in setting the signals into operation after the train has passed the entrance of the section ST to assure that the operating time of the signals before the train reaches the intersection is in accordance with the curve txu. The curve to of Fig. 5 illustrates the relationship between the curves trs and tsa: of Fig. 4 and from which curve to the shape of the cam 40 is obtained.

From an analysis of these curves and from the foregoing description of the operation of the apparatus at train speeds of 60, 40 and 20 miles per hour, it is apparent that with the apparatus constructed in the manner described the time measuring member (arm 56) is moved upward about its pivot at a variable rate and is restored at a uniform rate, and the highway crossing signals are set into operation at least 20 seconds prior to the arrival of a train at the intersection when the speed is 20 miles per hour and the operating time is increased for the higher speeds until at the maximum speedof 60 miles per hour the signals are set into operation 30 seconds prior to the arrival of the train at the intersection. As stated hereinbefore, my invention is not limited to the specific speed limits, operating time and track layout here described. The essential thing of my invention is that a time measuring member is moved away from a normal position at one rate during a measuring period the duration of which is determined by the speed of the train, and the member is then returned to its normal position at a second rate. In the form of the invention described hereinbefore said one rate is based upon the duration of the movement and upon a predetermined speed-time curve, and said second rate is based upon a predetermined speed-time curve, and the two rates are so proportioned that the highway crossing signals are set into operation at least a predetermined minimum interval prior to the arrival of a slow speed train at the intersection, and are set into operation a predetermined maximum interval prior to the arrival of a train traveling at the maximum speed and the operating time for trains of speeds intermediate these two speeds is made to vary between the minimum and maximum intervals in proportion to the speed. It will be apparent, however, that the cam surfaces of the cams 40 and 53 may be shaped so that the rate of movement of arm 56 away from its normal position may be a uniform rate and the rate of movement of the arm back toward its normal position may be something other than a uniform rate should it be so desired, and warning periods for the highway crossing signal may be substantially a constant interval prior to the arrival of a train at the intersection for all train speeds rather than the variable interval described hereinbefore.

Furthermore, with apparatus constructed in the manner here disclosed, a single operating unit (oscillator CT) is effective to actuate the time measuring device in both its forward and backward movements and also to operate the highway crossing signals.

In the event a train should stop or otherwise consume an unusually long time in the measuring section R-S, the cam 40 would be rotated an unusual movement clockwise and the arm 56 would be raised to the reverse position as illustrated by the dotted lines in Fig. 1. In this reverse position of the arm 56 the contact finger 63 makes engagement with the contact finger 55. Since the magnet 48 is energized while the train occupies the section R-S and its front contact 86 is closed, current is supplied from the B terminal of the current source over a simple circuit which includes contact 80, contact 63-65 and the winding of magnet 64 and that magnet is energized and attracts the armature 62 on the arm 56 with the result that the arm 56 is retained in this raised position notwithstanding the fact the cam may be rotated clockwise on past the position where it engages the cam follower 58. The spring 55 is effective to rotate the cam 53 and retain it in engagement with the cam follower 59 with the arm 56 in this reverse position, the gear 49 being in mesh with the gear 39. At such time as the train which stopped in the section R-S advances and moves into the section ST and shunts the track relay R the magnet 48 is deenergized, the cam 46 is released and assumes its normal position, and the arm 56 is released by the magnet 64 and is restored to its normal position by the cam 53 in response to operation of the oscillator CT. In the event a train stops in the operating section ST and the arm 56 is restored to its normal position, prior to the train vacating the section, further operation of the cam 53 is avoided due to the portion 10 of the gear 49.

A check circuit is provided and the normal position of the time measuring device is checked. This check circuit extends from the B battery terminal over the contact 60-6l, front contact 18 of the magnet 48 and thence to a signal 19. In the event the arm 56 fails to return to its normal position for any reason and the contact 606| is open, or if for any reason the magnet 48 is not energized and its front contact 18 is not closed, the. signal 19 is without current and assumes a stop position in the usual manner for such signals. The signal. 19 set at the stop position requires all trains to approach the highway H at a restricted speed. a

By making the relay R one element of an interlocking relay, the other element of which is governed by trafiic to the left of the highway H, the highway crossing signals SI and S2 may be governed in the usual manner for trains moving against the normal direction of trafiic. The relay R may be provided with a back contact 8| and current supplied directly to the signal lamps through the contacts I 9-20 and 2|22 during the time a train occupies the positive operating section TV if desired.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In, combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a time element device including a control member and two cams for reversibly operating said member in response to a train traveling different portions of the track in approaching the intersection, and means governed by said control member for starting the operation of said signal a variable time interval before a train reaches the intersection, which interval increases in proportion to the speed of the train.

2. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a time element device including a control member and two cams for reversibly operating said member in response to a train traveling difi'erent portions of the track in approaching the intersection, and means governed by said control member for starting the operation of said signal a variable time interval before a train reaches the intersection, which interval increases from a predetermined minimum interval in proportion to the speed of the train. I 3. In a signaling system for highway crossings on railroads, the combination with a signal located adjacent the crossing, of a time element device including two cams controlled by a train approaching the crossing for reversibly operating a control member, and means governed by said member for actuating said signal a predetermined time interval prior to the arrival of each train at the crossing, which interval increases in proportion to the speed of the train.

4. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, means responsive to the speed of a train approaching a fixed point to the rear of the highway including a control member and two cam members eifective to reversibly operate the control member, and

means governed by said control member for setting the signal into operation a time interval after the train reaches said fixed point, which interval is the difference between two factors at least one of which varies inversely as the speed of the train and whereby the operating time of the signal before the train reaches the intersection is made to increase in proportion to the speed of the train.

5. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, means responsive to the speed of a train approaching a fixed point to the rear of the highway including a control member and two cam members effective to reversibly operate the control member, and means governed by said control member for setting the signal into operation a time interval after the train reaches said fixed point, which interval is the difference between two factors one of which varies inversely as the speed of the train and the other of which varies in accordance with a predetermined speed-time curve and whereby the operating time of the signal before the train reaches the intersection is made to increase from a predetermined interval in proportion to the speed of the train.

6. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, means responsive to the speed of a train approaching a fixed point to the rear of the. highway including a control member and two cam members effective to reversibly operate the control member, and means governed by said control member for setting the signal into operation a time interval after the train reaches said fixed point, which interval is the difference between two factors one of which varies inversely as the speed of the train and the other of which varies in accordance with a predetermined speed-time curve whereby substantially a constant predetermined operating period of the signal before a train reaches the intersection for all speeds below a given speed is obtained and the operating time is increased in accordance with the speed for all speeds above said given speed.

7. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, means responsive to the speed of a train approaching a fixed point to the rear of the highway including a control member and two cam members effective to reversibly operate the control member, and means governed by said control member for setting the signal into operation a time interval after the train reaches said fixed point which varies in accordance with a predetermined speedtime curve whereby the signal is set into operation before the train reaches the intersection a period of time that increases in proportion to the speed of the train.

8. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a member normally occupying one position, means for moving said member away from said one position at a variable rate during the time interval required for a train approaching said highway to traverse a fixed distance, means eifective when the train' has traversed said fixed distance for restoring said member to said one position at a uniform rate, and means responsive to the position of said member for controlling said signal.

9. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, said track being divided to form two sections on one side of the highway, a track circuit including a track relay for each section, a time measuring device including a member normally occupying one position, an operating unit set into operation when a train approaching the highway releases the track relay of either track section, means controlled jointly by said operating unit and the track relay for the section nearer the highway when energized to move said member away from said one position at a variable rate, means controlled jointly by the operating unit and the track relay of said section nearer the highway when released to move said member towards its normal position at a uniform rate, and means controlled by the position of said member for controlling said signal.

10. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a time measuring device including an element normally occupying a given position, an operating unit, means controlled by a train approaching the intersection for actuating said unit, means governed by said operating unit when actuated for operating the device to move said element away from said given position at a variable rate during the interval the train is traveling at fixed distance in the rear of the highway, meansgoverned by said operating unit when actuated for operating the device to move said element toward said given position at a uniform rate in response to the train having traveled said fixed distance, and means controlled by said operating unit for operating said signal when said element is returned to said given position.

11. In combination, a stretch of railway track intersected by a highway, said track being divided to form two sections on one side of the highway, a highway crossing signal, a time measuring device including a ratchet gear and a circuit controlling element which element normally occupies its circuit closing position, means efiective to actuate said ratchet gear in its forward direction in response to a train occupying either one of said sections, means operated by said gear to move said element away from its normal position in response to the train occupying the more remote section, other means operated by said gear to move said element toward its normal position in response to the train occupying the section nearer the highway, and means controlled by the train effective to operate said signal when said element is moved to its normal position.

12. In combination, a stretch of railway track intersected by a highway, a highway crossing signal, a time measuring device including a ratchet gear and a circuit controlling element, which element normally occupies a given posi-. tion, means effective to actuate the ratchet gear in its forward direction in response to a train approaching the highway, means operated by said gear to move said element away from said given position at a variable rate while the train approaches a fixed point in the rear of the highway, other means operated by said gear to move said element toward said given position at a uniform rate in response to the train having reached the fixed point in the rear of the highway, and means controlled by the train efiective to operate said signal when said element is moved to said given position.

13. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a time measuring device including an oscillating armature, a ratchet gear and a circuit controlling element, said ratchet gear operated in its forward direction in step with oscillations of the armature and said element normally occupying a given position; a circuit including a winding effective when energized to actuate said armature, a first means operated by said gear and including a first cam effective to move said element away from the given position, a second means operated by said gear and including a second cam effective to move said element toward said given position, means controlled by a train approaching the intersection for energizing said winding and for first rendering said first means effective and then subsequently rendering said second means effective, and an operating circuit controlled by said element for operating the signal.

14. In combination, a stretch of railway track intersected by a highway, highway crossing signal located at the intersection, a time measuring device including a motor element and a circuit controlling element which normally occupies a given position, a circuit efiective when energized to actuate said motor element, a first means operated by said motor element and including a first cam effective to move said circuit controlling element away from said given position, a second means operated by said motor element and including a second cam effective to move the circuit controlling element toward said given position, means controlled by a train approaching the intersection for energizing said circuit and for successively rendering said first and second means efiective, and an operating circuit controlled by said circuit controlling element for operating said signal.

15. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a circuit controlling element normally occupying a given position, means including a first cam controlled by a train approaching a fixed point to the rear of the intersection for moving said element away from said given position, means including a second cam controlled by a train upon reaching said fixed point for moving said element toward said given position, and means controlled by said element for operating the signal.

16. In combination, a stretch of railway track, a highway crossing signal located at the intersection, said track divided to form two sections on one side of the highway, a track circuit including a track relay for each section, a time measuring means including a circuit controlling element and two cams capable of reversibly driving said element, means including a back contact of the track relay for the section more remote from the intersection for operating the time measuring means to drive said element by a particular one of said cams, other means including a back contact of the track relay for the section nearer the intersection for operating the time measuring means to drive said element by the other cam, and means controlled by the position of said element for operating said signal.

1'7. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a time measuring means including a circuit controlling element and two cams capable of driving said element away from and toward a given position but normally inactive, a first means controlled by a train while traveling a given distance in approaching the intersection for rendering said time measuring means active to drive said element away from its given position through a first one of said cams, other means controlled by the train when it has traveled said given distance for rendering said time measuring means active to drive said element from the point to which it had been advanced back toward its given position through the second one of said cams, and operating means controlled by said element when it reaches its given position for starting the operation of the signal.

18. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, measuring means including a first and a second cam which are capable of being rotated about a first and a second center respectively, a circuit controlling element capable of being moved away from and toward a normal position, means controlled by a train approaching a fixed point to the rear of the intersection for causing said measuring means to operate said first cam to move said element away from its given position, other means controlled by the train upon reaching said fixed point for causing the measuring means to operate said second cam to move said element back to its normal position whereby said element is moved away from its normal position at one rate and is returned to its normal position at a second rate, and operating means controlled by said element to govern said signal.

19. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section, a highway crossing signal located at the intersection, a circuit controlling element biased to a normal position, driving means controlled by a train in traveling the measuring section to move said element away from said normal position to measure the speed of the train, a cam, means effective when the train enters the operating section to render said driving means ineffective and to thereafter cause said cam to restrain movement of said element by its bias, means efiective while the train occupies the operating section to actuate said cam to permit the element to return gradually to its normal position through a time interval which depends upon the time consumed by th train in traveling the measuring section, and means controlled by said element for operating the signal.

20. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section, a highway crossing signal located at the intersection, a circuit controlling element biased to a normal position, driving means controlled by a train in traveling the measuring section to move said element away from said normal position to measure the speed of the train, means effective when the train enters the operating section to render said driving means ineffective, means effective while the train occupies such operating section and including a cam for governing the return of said element to said normal position under the influence of its bias, and means controlled by said element for operating the signal.

21. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section, a highway crossin signal located at the intersection, a circuit controlling element biased to a normal position, driving means controlled by a train in traveling the measuring section to move said element away from said normal position' to measure the speed of the train, means effective when the train enters the operating section to render said driving means in-efiective, means effective while the train occupies such operating section and including a cam for governing the return of said element to said normal position under the influence of its bias, said cam so shaped as to cause the element to return to its normal position in accordance with the time consumed by the train in traveling the measuring section and in accordance with a predetermined period of warning operation for said signal, and means controlled by said element for governing the warning operation of the signal.

22. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section, a highway crossing signal located at the intersection, a circuit controlling element biased to a normal position, driving means controlled by a train in traveling the measuring section and including a cam to move said element away from. said normal position at a rate predetermined by the shape of the cam, means controlled by the train when it enters the operating section to render said driving mean-s ineffective, means con" trolled by the train while it occupies the operating section to restrain movement of said element by its bias and to cause the element to return gradually to its normal position through a time interval which depends upon the time consumed by the train in traveling the measuring section, and means controlled by said element for operating the signal.

23. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section, a highway crossing signal located at the intersection, a circuit controlling element biased to a normal position, a cam, driving means set into operation by a train entering the measuring section to actuate the cam to drive said element away from said normal position at a rate predetermined by the shape of the cam for positioning the element in accordance with the time consumed by the train in traveling the measuring section, means: controlled by the train when it enters the operating section to render said driving means inefiective, means controlled by the train while it occupies the operating section to retrain movement of said element by its bias and to cause the element to gradually return to its normal position, and means controlled by said element for operating the signal.

'24. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section, a highway crossing signal located at the intersection, a circuit controlling element, a cam, driving means set into operation by a train entering the measuring section to actuate the cam to drive said element in a forward direction at a rate predetermined by the shape of the cam for positioning the element in accordance with the timeconsumed by the train in traveling the measuring section, means controlled by the train when it enters the operating section to render said driving means ineffective, means controlled by the train while it occupies the operating section to cause said element to gradually move in a backward direction from the position to which it had advanced, and means controlled by said element for operating the signal.

25. In combination, a stretch oi railway track intersected by a highway and divided into a measuring section and an operating section, said measuring section being relatively short compared with the operating section, a highway crossing signal located at the intersection, a circuit controlling element, driving means controlled by a train in traveling the measuring section and including a cam to drive said element in a forward direction at a rate proportional to the ratio of the relative lengths of saidmeasuring and operating sections for positioning the element according to the time consumed by the train in traveling the measuring section, means controlled by the train when it enters the operating section to render said driving means ineffective, means controlled by the train while it occupies the ope-rating section to cause said element to gradually move in a backward direction from the position to which it had advanced, and means controlled by said element for operating the signal.

26. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a time element device including a control member and two cams for reversibly operating said member in response to a train traveling different portions of the track in approaching the intersection, and means governed by said control member for starting the operation of said signal a variable time interval before a train reaches the intersection, which interval changes from a predetermined minimum interval in proportion to the speed of the train.

2'7. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a time element device including a control member biased to a. normal position and two cams one of which is ei fective to govern movement of the member away from the normal position while a train approaching the intersection is traveling a first portion of the track and the other of which cams is effective to, govern movement of the member back to the nonnal position while the train occupies a second portion of the track, and means governed by said control member for starting the operation of said signal a variable time interval before the train reaches the intersection, which interval changes from a predetermined minimum interval in proportion to the speed of the train.

CRAWFORD E. STAPLES. 

